Light-emitting element

ABSTRACT

A light-emitting element comprises a light-emitting semiconductor stack comprising a first semiconductor layer, a second semiconductor layer on the first semiconductor layer, and a light-emitting layer between the first semiconductor layer and the second semiconductor layer; a first electrode comprising an contact area and an extension electrically connected to the first semiconductor layer, wherein the extension is connected to the contact area; a second electrode on the second semiconductor layer; and a first conductive part and a second conductive part formed on the light-emitting semiconductor stack and respectively electrically connected to the first electrode and the second electrode, wherein the extension is formed beyond a projected area of the second conductive part and not covered by the first conductive part, and the contact area is covered by the first conductive part.

REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 14/718,242, filed on May 21, 2015, now pending,which is a continuation application of U.S. patent application Ser. No.14/098,911, filed on Dec. 6, 2013, now pending, which claims the rightof priority based on TW application Serial No. 101146339, filed on Dec.7, 2012, and the contents of which are hereby incorporated by referencesin their entireties.

TECHNICAL FIELD

The present application relates to a light-emitting element, andparticularly to a light-emitting element such as a flip-chiplight-emitting diode, which comprises a conductive contact layer.

DESCRIPTION OF BACKGROUND ART

Optoelectronic devices, such as light-emitting diodes, are now widelyused for optical display devices, traffic lights, data storage devices,communication devices, lighting devices, and medical devices.

Besides, the light-emitting diode as mentioned above is able to combinewith other structures to form a light-emitting device. FIG. 6schematically shows a conventional light-emitting device. As shown inFIG. 6, a conventional light-emitting device 5 comprises a submount 52comprising an electrical circuit 54; a solder 56 on the submount 52,wherein the solder is used for stabilizing an LED 51 on the submount 52and thus renders the LED 51 electrically connected to the electricalcircuit 54 of the submount 52, wherein the LED 51 comprises a substrate53; and an electrical connecting structure 58 used for electricallyconnecting an electrode 55 of the LED 51 to the electrical circuit 54 ofthe submount 52; wherein the submount 52 is a lead frame or alarge-scale mounting substrate.

SUMMARY OF THE DISCLOSURE

A light-emitting element, comprising: a substrate; a light-emittingsemiconductor stack on the substrate, a first protection layer on thelight-emitting semiconductor stack; a reflective layer on the firstprotection layer; a barrier layer on the reflective layer; a secondprotection layer on the barrier layer; and a conductive contact layer onthe second protection layer; wherein the conductive contact layercomprises a first conductive part and a second conductive part, and asurface area of an upper surface of the first conductive part isdifferent from a surface area of an upper surface of the secondconductive part.

A light-emitting element, comprising: a substrate; a light-emittingsemiconductor stack on the substrate, a first protection layer on thelight-emitting semiconductor stack; a reflective layer on the firstprotection layer; a barrier layer on the reflective layer; a secondprotection layer on the barrier layer; and a conductive contact layer onthe second protection layer; wherein the conductive contact layercomprises a first conductive part and a second conductive part, and asurface area of an upper surface of the first conductive part is equalto a surface area of an upper surface of the second conductive part.

A light-emitting element comprises a light-emitting semiconductor stackcomprising a first semiconductor layer, a second semiconductor layer onthe first semiconductor layer, and a light-emitting layer between thefirst semiconductor layer and the second semiconductor layer; aplurality of extensions formed on the first semiconductor layer; and afirst conductive part and a second conductive part formed on thelight-emitting semiconductor stack and respectively electricallyconnected to the first semiconductor layer and the second semiconductorlayer, wherein one of the plurality of extensions is formed beyond aprojected area of the second conductive part and not covered by thefirst conductive part.

A light-emitting element comprises a light-emitting semiconductor stackcomprising a first semiconductor layer, a second semiconductor layer onthe first semiconductor layer, and a light-emitting layer between thefirst semiconductor layer and the second semiconductor layer; a firstelectrode comprising an contact area and an extension electricallyconnected to the first semiconductor layer, wherein the extension isconnected to the contact area; a second electrode on the secondsemiconductor layer; and a first conductive part and a second conductivepart formed on the light-emitting semiconductor stack and respectivelyelectrically connected to the first electrode and the second electrode,wherein the extension is formed beyond a projected area of the secondconductive part and not covered by the first conductive part, and thecontact area is covered by the first conductive part.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view of a light-emitting element in accordance with oneof the embodiments of the present application;

FIG. 1B is a cross-sectional diagram along the line of A-A′ inaccordance with the light-emitting element of the present applicationshown in FIG. 1A;

FIG. 1C is a cross-sectional diagram along the line of B′-B′ shown inFIG. 1A in accordance with one of the embodiments of the light-emittingelement of the present application;

FIG. 1D is a cross-sectional diagram along the line of B′-B′ shown inFIG. 1A in accordance with one of the embodiments of the light-emittingelement of the present application;

FIG. 1E is a three dimensional view in accordance with thelight-emitting element of the present application shown in FIG. 1A;

FIG. 2A is a top view of a light-emitting element in accordance with oneof the embodiments of the present application;

FIG. 2B is a cross-sectional diagram along the line of C-C′ inaccordance with the light-emitting element of the present applicationshown in FIG. 2A;

FIG. 3 schematically shows a light-generating element in accordance withone of the embodiments of the present application;

FIG. 4 schematically shows a backlight module in accordance with one ofthe embodiments of the present application;

FIG. 5 is an exploded view of a light bulb in accordance with one of theembodiments of the present application; and

FIG. 6 schematically shows a conventional light-emitting device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Exemplary embodiments of the present application will be described indetail with reference to the accompanying drawings hereafter. Thefollowing embodiments are given by way of illustration to help thoseskilled in the art fully understand the spirit of the presentapplication. Hence, it should be noted that the present application isnot limited to the embodiments herein and can be realized by variousforms. Further, the drawings are not precise scale and components may beexaggerated in view of width, height, length, etc. Herein, the similaror identical reference numerals will denote the similar or identicalcomponents throughout the drawings.

FIG. 1A is a top view of a light-emitting element in accordance with oneof the embodiments of the present application. FIG. 1B is across-sectional diagram along the line of A-A′ of FIG. 1A. As shown inFIGS. 1A and 1B, a light-emitting element 1 comprises a substrate 10; alight-emitting semiconductor stack 12 on the substrate 10; a firstprotection layer 11 on the light-emitting semiconductor stack 12; areflective layer 13 on the first protection layer 11; a barrier layer 15on the reflective layer 13 and covering and surrounding the reflectivelayer 13; a second protection layer 17 on the barrier layer 15 andcovering and surrounding the first protection layer 11, the reflectivelayer 13, and the barrier layer 15; and a conductive contact layer 19 onthe second protection layer 17. The light-emitting semiconductor stack12 comprises a first semiconductor layer 122 on the substrate 10; alight-emitting layer 124 on the first semiconductor layer 122; a secondsemiconductor layer 126 on the light-emitting layer 124. Thelight-emitting element 1 further comprises multiple first electrodes 121on the first semiconductor layer 122; and a second electrode 123 on thesecond semiconductor layer 126, wherein each first electrode 121comprises a contact area 125 and an extension area 127. In the presentembodiment, the multiple first electrodes 121 are physically separatedfrom one another, such as spatially separated from one another, and areelectrically connected to one another by a first conductive part 190, soas to reduce a portion of the light-emitting semiconductor stack 12 thatneeds to be removed. Thus, the light emitting area is increased. Thesecond protection layer 17 has a first through hole 172 and a secondthrough hole 174, wherein the first through hole 172 is above thecontact area 125, as shown in FIG. 1B, and the second through hole 174is above the barrier layer 15, as shown in FIG. 1A.

The conductive contact layer 19 is for receiving an external voltage andfor heat dissipation. The conductive contact layer 19 comprises a firstconductive part 190 and a second conductive part 191, and the conductivecontact layer 19 is composed of one or multiple metal materials. Themetal material comprises Cu, Sn, Au, Ni, Ti, Pt, Pb, AuSn alloy, Cu-Sn,Cu-Zn, Cu-Cd, Sn-Pb-Sb, Sn-Pb-Zn, Ni-Sn, Ni-Co, Au alloy, Au-Cu-Ni-Au,and the combinations thereof.

Referring to FIG. 1A, each extension area 127 of the first electrodes121 extends outwardly from one of the contact areas 125 so the extensionareas 127 cover larger area on the first semiconductor layer 122 toimprove current spreading. As shown in FIG. 1A, an end of each extensionarea 127 distant away from the contact areas 125 is under the secondconductive part 191, but the present disclosure is not limited to this,and the end of each extension area 127 can also protrude beyond aprojected area of the second conductive part 191. Referring to FIG. 1B,the first conductive part 190 is electrically connected to the contactareas 125 of the first electrodes 121 by the first through hole 172, andtherefore a current can flow from the first conductive part 190 to thefirst semiconductor layer 122 through the first electrodes 121, whereinthe first semiconductor layer 122 is under the second conductive part191. The second conductive part 191 is electrically connected to thebarrier layer 15 by the second through hole 174, and therefore a currentcan flow from the second conductive part 191 to the second semiconductorlayer 126 through the barrier layer 15, the reflective layer 13, and thesecond electrode 123. Referring to FIG. 1B, the first conductive part190 comprises a first width w1 and the second conductive part 191comprises a second width w2. In the present embodiment, the first widthw1 is smaller than the second width w2. A distance d between the firstconductive part 190 and the second conductive part 191 is at least about50 μm. More preferably, the distance d ranges from 70 to 150 μm. Adistance smaller than 50 μm leads to a short circuit, for example, priorto a process of soldering the light-emitting element 1 and a base (notshown), a solder paste is applied on the first conductive part 190 andthe second conductive part 191 respectively, if the distance d issmaller than 50 μm, the solder pastes on the first conductive part 190and the second conductive part 191 are easily in contact with eachother, and the contact then causes a short circuit; or during a processof an eutectic bonding between the light-emitting element 1 and a base,an inaccurate alignment between the light-emitting element 1 and thebase leads to a misalignment between the first conductive part 190 andone of the electrodes on the base, and between the second conductivepart 191 and another electrode of the base, and then the misalignmentcauses a short circuit.

In another embodiment, the first conductive part 190 comprises a firstheight h1 defined as a distance between an upper surface of the firstconductive part 190 and an upper surface of the substrate 10, and thesecond conductive part 191 comprises a second height h2 defined as adistance between an upper surface of the second conductive part 191 andthe upper surface of the substrate 10, wherein the first height h1 issubstantially equal to the second height h2. As a result, a heightdifference between the first conductive part 190 and the secondconductive part 191, which causes a failure of a connection between abase and the light-emitting element 1, is prevented. Thus, the qualityis improved. The first width w1 of the present embodiment is not limitedto smaller than the second width w2. The first width w1 can be largerthan or equal to the second width w2 as well.

In another embodiment, referring to FIG. 1B, the first conductive part190 comprises a first height balancer 192 filled in the first throughhole 172, preferably on the second protection layer 17, and the secondconductive part 191 comprises a second height balancer 193 on the secondprotection layer 17. The first height balancer 192 and the second heightbalancer 193 can be used for adjusting the height of the firstconductive part 190 and the height of the second conductive part 191respectively, such as used for rendering the height of the firstconductive part 190 substantially equal to the height of the secondconductive part 191, that is, rendering the first height h1substantially equal to the second height h2.

In another embodiment, the first height balancer 192 of the firstconductive part 190 renders the first height h1 larger than the secondheight h2. In the case of soldering process, during the process ofsoldering the light-emitting element 1 and a base, when the surface areaof the upper surface of the second conductive part 191 is larger thanthe surface area of the upper surface of the first conductive part 190,the adhesion of second conductive part 191 to the base is stronger thanthe adhesion of the first conductive part 190 to the base since acontact area between the second conductive part 191 and the solder pasteis larger. The adhesion difference causes the substrate 10 to warpduring the heating process and thus results in a height difference,which further causes the first conductive part 190 to peel from thebase. As a result, when the first height h1 is larger than the secondheight h2, the first height h1 can reduce the height difference causedby the warp of the substrate 10, and thus prevent the first conductivepart 190 from peeling from the base. Besides, the height differencebetween the first height h1 and the second height h2 can also alleviatea problem of a height difference of the electrodes on the base or amisalignment of the electrodes, and thus further mitigate a problem ofthe first conductive part 190 peeling from the base, wherein the heightdifference of the electrodes is caused by the warp of the substrate 10,the design of the base or the unevenness of the surface, and themisalignment of the electrodes is resulted from a factor related to themanufacturing process, such as vibration or gas flow. Specifically, thefirst height h1 is about 1 to 10 μm larger than the second height h2.

The substrate 10 is used for supporting the light-emitting semiconductorstack 12 and other layers or structures thereon. The material of thesubstrate 10 can be transparent material comprising sapphire, diamond,glass, epoxy, quartz, acrylics, Al₂O₃, GaAs, ZnO or AlN, whereinsapphire and GaAs can be used for growing a light-emitting semiconductorstack.

The light-emitting semiconductor stack 12 can be directly grown on thesubstrate 10, or can be fixed on the substrate 10 by a bonding layer(not shown). The material of the light-emitting semiconductor stack 12can be semiconductor material comprising one or more elements selectedfrom the group consisting of Ga, Al, In, P, N, Zn, Cd, and Se. Theelectrical polarity of the first semiconductor layer 122 is differentfrom that of the second semiconductor layer 126. The light-emittinglayer 124 emits light having one or more colors and the structure oflight-emitting layer 124 can be single heterostructure (SH), doubleheterostructure (DH), double-side double heterostructure (DDH),multi-quantum well (MQW) or quantum dots.

The first electrodes 121 and the second electrode 123 are used forconducting a current, and the material of the first electrodes 121 andthe second electrode 123 is transparent material or metal material,wherein the transparent material comprises indium tin oxide (ITO),indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimonytin oxide (ATO), aluminium zinc oxide (AZO), zinc tin oxide (ZTO), zincoxide (ZnO), gallium doped zinc oxide(GZO), indium zinc oxide (IZO),AlGaAs, GaN, GaP, GaAs, GaAsP, or diamond-like carbon (DLC), and themetal material includes Cu, Sn, Au, Ni, Pt, Al, Ti, Cr, Pb, Cu-Sn,Cu-Zn, Cu-Cd, Sn-Pb-Sb, Sn-Pb-Zn, Ni-Sn, Ni-Co, Au alloy, Au-Cu-Ni-Au orcombinations thereof.

The first protection layer 11 and/or the second protection layer 17 areused for electrically insulating the first conductive part 190 and thesecond conductive part 191 from the reflective layer 13, and forpreventing the reflective layer 13 from a damage caused by the firstconductive part 190 and the second conductive part 191. The firstprotection layer 11 and/or the second protection layer 17 are used forsecuring the reflective layer 13 and improving the mechanical strengthof the light-emitting element 1. The material of the first protectionlayer 11 and the second protection layer 17 can be an insulatingmaterial comprising polyimide (PI), benzocyclobutene (BCB),prefluorocyclobutane (PFCB), MgO, epoxy, Sub, acrylic resin, cyclicolefin polymers (COC), polymethylmethacrylate (PMMA), polyethyleneterephthalate (PET), polycarbonate (PC), polyetherimide, fluorocarbonpolymer, glass, Al₂O₃, SiO_(x), TiO₂, SiN_(x) or spin-on glass.

The reflective layer 13 reflects the light emitted from thelight-emitting semiconductor stack 12. The material of the reflectivelayer 13 comprises Cu, Al, Sn, Au, Ag, Ti, Ni, Pt, TiW alloy, Ag-Ti,Ni-Sn, Au alloy, Ni-Ag or Ti-Al.

The barrier layer 15 is used for avoiding an ionic diffusion from thereflective layer 13 and/or for enhancing the adhesion between thereflective layer 13 and the second protection layer 17. The material ofthe barrier layer 15 comprises Cu, Al, Sn, Au, Ag, Ti, Ni, Pt, TiWalloy, Ag-Ti alloy, Ni-Cr, Ag-Ti, Ni-Sn, Au alloy, Ni-Ag, or Ti-Al.

FIG. 1C is a cross-sectional diagram along the line of B′-B′ shown inFIG. 1A in accordance with another embodiment. Referring to FIG. 1C, thelaminated layer structures above the substrate 10 of the light-emittingelement 1 can comprise similar profiles, for example, each comprisesaside face inclined relative to the substrate 10. Specifically, as shownin FIG. 1C, the extension area 127 comprises an upper face 1270, a lowerface 1272 opposite to the upper face 1270, a side face 1274 between theupper face 1270 and the lower face 1272, and an angle Θ between the sideface 1274 and the lower face 1272, wherein the angle Θ ranges from about15 degrees to 70 degrees, more preferably, from about 30 degrees to 45degrees. Compared with an extension area comprising an angle of 90degrees between the side face and the lower face, the angle Θ of theextension area 127 causes the side face 1274 to have a more gentleslope, and therefore the structures formed on the extension area 127such as the first protection layer 11, do not have deficiency instructure such as insufficient of thickness, which is resulted from asteep side face, and the deficiency may further result in instabilityand a lowering yield of a optoelectronic device. Accordingly, thestability of the light-emitting element 1 is improved. The firstconductive part 190 and the second conductive part 191 can each have aconcave-convex profile. In another embodiment, as shown in FIG. 1D, eachupper face of the first conductive part 190 and the second conductivepart 191 is flat since the first conductive part 190 and the secondconductive part 191 have the first height balancer 192 on the secondprotection layer 17 and the second height balancer 193 on the secondprotection layer 17 respectively. Specifically, the first heightbalancer 192 is in the first through hole 172 and on part of the secondprotection layer 17. The second height balancer 193 is on part of thesecond protection layer 17 and filled in the second through hole 174.

FIG. 1E is a three dimensional view in accordance with thelight-emitting element 1 of the present application shown in FIG. 1A. Asshown in FIG. 1E, the second protection layer 17 is on the substrate 10,and the first conductive part 190 and the second conductive part 191 areon the second protection layer 17.

FIG. 2A is a top view of a light-emitting element 2 in accordance withanother embodiment of the present application, and FIG. 2B is across-sectional diagram along the line of C-C′ in accordance with thelight-emitting element 2 of the present application shown in FIG. 2A. Asshown in FIG. 2A, the first electrode 20 of the light-emitting element 2has multiple contact areas 202, multiple extension areas 204 and aconnecting area 206 connecting the multiple contact areas 202. The firstconductive part 190 is electrically connected to the contact areas 202of the first electrode 20 by the first through hole 172, and therefore acurrent can flow from the first conductive part 190 to the firstsemiconductor layer 122 through the first electrode 20, wherein thefirst semiconductor layer 122 is under the second conductive part 191.Besides, the second protection layer 17 electrically insulates the firstconductive part 190 from the second semiconductor layer 126. In thepresent embodiment, the surface area of the upper surface of the firstconductive part 190 can be substantially equal to the surface area ofthe upper surface of the second conductive part 191. As a result, duringa process of soldering the light-emitting element 2 and a base, apeeling problem of the first conductive part 190 or the secondconductive part 191 from the base caused by the adhesion difference tothe base is avoided, wherein the adhesion difference is caused by thedifference in surface area of the upper surface of the first conductivepart 190 and the upper surface of the second conductive part 191.Accordingly, the quality of the soldering process is improved. Morepreferably, when the surface area of the upper surface of the firstconductive part 190 is substantially equal to the surface area of theupper surface of the second conductive part 191, the height of the firstconductive part 190 is substantially equal to the height of the secondconductive part 191, that is, the first height h1 is substantially equalto the second height h2.

In another embodiment, a ratio of the surface area of the upper surfaceof the first conductive part 190 to the surface area of the uppersurface of the second conductive part 191 ranges from about 0.8 to 1.2,more preferably, from about 0.9 to 1.1. In another embodiment, as shownin FIG. 2B, a first width w1 of the first conductive part 190 issubstantially equal to a second width w2 of the second conductive part191. In another embodiment, a ratio of the first width w1 to the secondwidth w2 ranges from about 0.8 to 1.2, more preferably, from about 0.9to 1.1.

Referring to FIG. 2A, the first conductive part 190 does not cover apart of each contact area 202, so the part of each contact area 202and/or the second protection layer 17 on the part of each contact area202 are exposed. Prior to a process of eutectic bonding between thefirst conductive part 190 and a base, a solder flux is applied on thesurface of the first conductive part 190. After the eutectic bonding,the solder flux residue needs to be cleaned so as to prevent thefollowing packaging process being affected by the solder flux residue.In the present embodiment, the exposed second protection layer 17 isnear the edge of the light-emitting element 2, and thus a solder fluxresidue remained between the light-emitting element 2 and the base iseasy to clean through the exposed second protection layer 17.Accordingly, the quality of the following packaging process is improved.

FIG. 3 schematically shows a light-generating element 3 of an embodimentof the present application. The light-generating element 3 comprises alight-emitting element of any one of the embodiments as mentioned above.The light-generating element 3 can be a lighting device, such as astreet light, a headlight, or an interior lighting, or can be a trafficlight or a backlight of a backlight module of a flat panel display. Thelight-generating element 3 comprises a light source 31 comprising alight-emitting element of any embodiment as mentioned above, a powersupply system 32 used for providing a current to the light source 31,and a control element used for controlling the power supply system 32.

FIG. 4 schematically shows a backlight module 4 of an embodiment of thepresent application. The backlight module 4 comprises a light-generatingelement 3 as mentioned above and an optical element 41. The opticalelement 41 processes the light generated by the light-generating element3, such as diffuses the light generated by the light-generating device3. The backlight module 4 is applicable to flat panel displays.

FIG. 5 is an exploded view of a light bulb 6 in accordance with one ofthe embodiments of the present application. The light bulb 6 comprises alamp 61, a lens 62 disposed in the lamp 61, a lighting module 64disposed under the lens 62, a lamp holder 65 comprising a heat sink 66,wherein the lighting module 64 is used for holding the lighting module64, a connecting part 67, and an electrical connector 68, wherein theconnecting part 67 connects the lamp holder 65 to the electricalconnector 68. The lighting module 64 comprises a carrier 63 and multiplelight-emitting elements 60 of any one of the embodiments as mentionedabove, wherein the multiple light-emitting elements 60 are on thecarrier 63.

The foregoing description of preferred and other embodiments in thepresent disclosure is not intended to limit or restrict the scope orapplicability of the inventive concepts conceived by the Applicant. Inexchange for disclosing the inventive concepts contained herein, theApplicant desires all patent rights afforded by the appended claims.Therefore, it is intended that the appended claims include allmodifications and alterations to the full extent that they come withinthe scope of the following claims or the equivalents thereof.

What is claimed is:
 1. A light-emitting element, comprising: alight-emitting semiconductor stack comprising: a first semiconductorlayer; a second semiconductor layer on the first semiconductor layer;and a light-emitting layer between the first semiconductor layer and thesecond semiconductor layer; a first electrode comprising an contact areaand an extension electrically connected to the first semiconductorlayer, wherein the extension is connected to the contact area; a secondelectrode on the second semiconductor layer; and a first conductive partand a second conductive part formed on the light-emitting semiconductorstack and respectively electrically connected to the first electrode andthe second electrode, wherein the extension is formed beyond a projectedarea of the second conductive part and not covered by the firstconductive part, and the contact area is covered by the first conductivepart.
 2. The light-emitting element according to claim 1, furthercomprising a reflective layer on the second electrode; and a barrierlayer on the reflective layer.
 3. The light-emitting element accordingto claim 2, further comprising a first protection layer on thelight-emitting semiconductor stack, a second protection layer comprisinga first through hole on the contact area of the first electrode and asecond through hole on the barrier layer.
 4. The light-emitting elementaccording to claim 3, wherein the first conductive part is formed in thefirst through hole and extended onto a surface of the second protectionlayer, and the second conductive part is formed in the second throughhole and extended onto another surface of the second protection layer.5. The light-emitting element according to claim 3, wherein theextension of the first electrode is covered by the second protectionlayer.
 6. The light-emitting element according to claim 3, wherein partof the barrier is between the first protection layer and the secondprotection layer.
 7. The light-emitting element according to claim 1,wherein an end of the extension is formed beyond the projected area ofthe second conductive part and not covered by the first conductive part.8. The light-emitting element according to claim 1, wherein the secondelectrode comprises transparent conductive material.
 9. Thelight-emitting element according to claim 2, wherein the reflectivelayer and the barrier layer comprises metal material.
 10. Thelight-emitting element according to claim 2, wherein the reflectivelayer is formed between the barrier layer and the second electrode. 11.A light-emitting element, comprising: a light-emitting semiconductorstack comprising: a first semiconductor layer; a second semiconductorlayer on the first semiconductor layer; and a light-emitting layerbetween the first semiconductor layer and the second semiconductorlayer; a first electrode comprising multiple contact areas and multipleextension areas, wherein the multiple contact areas are physicallyseparated from one another; and a first conductive part and a secondconductive part are formed on the light-emitting semiconductor stack andrespectively electrically connected to the first semiconductor layer andthe second semiconductor layer, wherein the multiple extensions areformed beyond a projected area of the second conductive part and notcovered by the first conductive part, and the multiple contact areas arecovered by the first conductive part.
 12. The light-emitting elementaccording to claim 11, wherein the first conductive part and the secondconductive part comprise a distance there between, and the distance isat least 50 μm.
 13. The light-emitting element according to claim 11,further comprising a second electrode on the second semiconductor layer;a reflective layer on the second electrode; and a barrier layer on thereflective layer.
 14. The light-emitting element according to claim 13,further comprising a first protection layer on the light-emittingsemiconductor stack, a second protection layer comprising a firstthrough hole on one of the multiple contact areas of the first electrodeand a second through hole on the barrier layer.
 15. The light-emittingelement according to claim 14, wherein the first conductive part isformed in the first through hole and extended onto a top surface of thesecond protection layer and the second conductive part is formed in thesecond through hole and extended onto the top surface of the secondprotection layer.
 16. The light-emitting element according to claim 14,wherein the multiple extensions of the first electrode are covered bythe second protection layer.
 17. The light-emitting element according toclaim 14, wherein part of the barrier is between the first protectionlayer and the second protection layer.
 18. The light-emitting elementaccording to claim 11, wherein an end of each of the multiple extensionsis formed beyond the projected area of the second conductive part andnot covered by the first conductive part.
 19. The light-emitting elementaccording to claim 13, wherein the second electrode comprisestransparent conductive material.
 20. The light-emitting elementaccording to claim 13, wherein the reflective layer and the barrierlayer comprises metal material.